This invention relates to birdbath and animal watering devices such as used for practical and decorative purposes, and in particular to a self cleaning and refilling apparatus.
There are many types of birdbaths, most a simple bowl on a mounting pole, with physical stability, and perhaps good looks being the only requirements. They are usually dirty and dry. If water is in the birdbath it is usually dirty, unsanitary, breading mosquitoes, and bacteria. Few owners have the time and put out the effort to keep them clean and filled with fresh clean water for the birds and animals.
Inventors created self cleaning birdbaths. U.S. Pat. No. 3,696,786 to Garwood (1972) is described as “A self cleaning bird bath” but in fact only emptied itself of dirty water, if water from some outside source is provided. It would only be refilled and left full if after it righted itself at the end of the emptying cycle the unknown water source then filled it, stopping before causing the bowl to empty itself again. There was no cleaning action what so ever and no guarantee that the bowl would contain any water if operated by rain. If it were manually filled to cause emptying to occur and then filled, rain could still cause unwanted operation ending up empty. The bowl had internal channels with ports to the inside and underneath to the counter balance bucket. It also had a pivot assembly and actuation arm attachment points. The counter balance bucket with holes had to be matched to over balance the asymmetrically weighted bowl when full but not when empty. All these parts made the design expensive to make. This design has no freeze damage protection.
Mr. Garwood's next version U.S. Pat. No. 3,995,591 resolved the problems of unreliable action by using water under pressure delivered by pipe or hose to actuate the cleaning and filling cycle. There was still no cleaning action, just emptying the water and refilling the bowl. This unit was even more expensive to make. It used a hydraulic piston and cylinder to operate the emptying of the bowl. Water pressure would have to be regulated for proper function unless manually adjusted for emptying and filling. This design has no freeze damage protection.
Then came U.S. Pat. No. 4,630,569 to Dieleman in 1986. This self cleaning birdbath is operated by water under pressure delivered by an underground pipe and provides a means of automatic operation and a little cleaning action. Cleaning is accomplished by filling the bowl with water at a pressure not sufficient to carry the water out of the bowl. Then water at that pressure continues to agitate the full bowl of water to clean the bowl. The indicated level of agitation of a full bowl of water does not get it very clean. A film of scum will easily stay behind after the cleaning stage. When the pressure is increased to empty the bowl the water is sprayed up and out in a cone, carrying with it the dirty water in the bowl from the cleaning stage, coming down beyond the rim and outside of the bowl. The main force of the sprayed cone does not directly strike the surface of the bowl. Some collateral spray mist that falls on some part of the surface of the bowl drains back to the center and is carried out with the spray as it is leaving the nozzle. Because the nozzle is fully raised at this point there will be water from the agitation cycle in the bottom of the bowl up to the level of the nozzle in its raised position. When the cleaning cycle is done the bowl will drain itself if there is any small leak anywhere in the plumbing system or joints between the bowl and sprinkler assembly. This sealing requirement has to stand up to an animal's weight that would be applied to one edge of the bowl by putting the fore feet on it while taking a drink. The required seals and leak proof fittings between all parts, including moving parts, make this design expensive to make and somewhat unreliable too. The fact that the sprinkler assembly, the adapter collar, and the bowl must be assembled and installed water tight, makes assembly and installation less than user friendly for the average person. This system is somewhat pressure sensitive because the return spring in the rising spray nozzle operates at a specific pressure. This system works best with regulation that is incorporated into the design and adds to the cost and complexity of the system, and it's installation. This system has no protection against freeze damage other than to manually shut off the water and drain the pipes making the system inoperable.